faker-ruby/faker · error · ArgumentError

Filters do not match any sciences

Error message

Filters do not match any sciences

What it means

Raised by Faker::Science.science when the combination of branch filters produces an empty set of sciences. BRANCHES maps each filter (:empirical, :formal, :natural, :social, :basic, :applied) to a list of science categories, and the filters are intersected; contradictory pairs like :empirical + :formal (empirical covers empirical_* categories, formal covers formal_*) share no categories, so selected becomes empty and ArgumentError is raised. Unknown branch symbols are silently ignored (BRANCHES.key? guard), so they never trigger this error.

Solutions

1. Use compatible filter combinations: at most one branch-type (:empirical or :formal) combined with at most one modifier (:natural/:social and/or :basic/:applied), e.g. science(:natural, :applied).
2. Call science with no arguments when you just want any science.
3. Guard compound selections before calling by intersecting Faker::Science::BRANCHES values yourself and skipping empty results.

Example fix

# before
Faker::Science.science(:empirical, :formal) # ArgumentError: contradictory filters

# after
Faker::Science.science(:formal, :applied) # 'Computer Science'

BRANCHES = Faker::Science::BRANCHES
selected = BRANCHES.values.flatten.uniq
branches.each { |b| selected &= BRANCHES[b] if BRANCHES.key?(b) }
Faker::Science.science(*branches) unless selected.empty?

def compatible_science_filters?(branches)
  b = Faker::Science::BRANCHES
  selected = b.values.flatten.uniq
  branches.each { |branch| selected &= b[branch] if b.key?(branch) }
  !selected.empty?
end

begin
  Faker::Science.science(*branches)
rescue ArgumentError
  Faker::Science.science # unfiltered
end

When it happens

Trigger: Faker::Science.science(:empirical, :formal) — the two filters intersect to an empty list and raise. Also :formal + :natural (natural only contains empirical_natural_* categories) raises. A single filter or none never raises.

Common situations: Building filter combinations programmatically from UI checkboxes and hitting mutually exclusive pairs; assuming any combination of valid filters is valid; not realizing misspelled filters (e.g. :nature) are ignored rather than validated, so the error only signals contradictory valid filters.

Related errors

• Familial connections can be left blank or #
• Invalid credit cards argument can be left blank or include #
• invalid period
• Supported colorizations are #
• Supported formats are #

AI-assisted analysis of faker-ruby/faker@cca4184947 (2026-08-21). Data as JSON: /api/errors/c469629eab599465. Report an issue: GitHub.

Appendix: source

Thrown at lib/faker/default/science.rb:37

      # @see https://en.wikipedia.org/wiki/Science#Branches_of_science
      # @see Faker::Educator.subject
      #
      # @param branches [Array<Symbol>]
      # @return [String]
      #
      # @example
      #   Faker::Science.science #=> "Space science"
      #   Faker::Science.science(:natural, :applied) #=> "Engineering"
      #   Faker::Science.science(:formal, :applied) #=> "Computer Science"
      #
      # @faker.version next
      def science(*branches)
        selected = BRANCHES.values.flatten.uniq
        branches.each do |branch|
          selected &= BRANCHES[branch] if BRANCHES.key? branch
        end

        raise ArgumentError, 'Filters do not match any sciences' if selected.empty?

        sciences = []
        selected.each do |branch|
          sciences += translate("faker.science.branch.#{branch}")
        end

        sample(sciences)
      end

      ##
      # Produces the name of a element.
      #
      # @return [String]
      #
      # @example
      #   Faker::Science.element #=> "Carbon"
      #
      # @faker.version 1.8.5

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